Install sendmail:

sudo apt-get -y install sendmail-bin mutt>

Install sendmail:

sudo apt-get -y install sendmail-bin mutt

Create a configuration file for mutt:

cd /home/pi
nano .muttrc

insert the followin content

# basic .muttrc for use with Gmail
# Change the following six lines to match your Gmail account details
set imap_user = ""
set imap_pass = ""
set smtp_url = "smtp://"
set smtp_pass = ""
set from = ""
set realname = "Firstname Lastname"
# # Change the following line to a different editor you prefer.
set editor = 'vim + -c "set textwidth=72" -c "set wrap"'
# Basic config
set folder = "imaps://"
set spoolfile = "+INBOX"
set imap_check_subscribed=yes
set hostname =
set mail_check = 120
set timeout = 300
set imap_keepalive = 300
set postponed = "+[GMail]/Drafts"
set header_cache=~/.mutt/cache/headers
set message_cachedir=~/.mutt/cache/bodies
set certificate_file=~/.mutt/certificates
set move = no
set include
set sort = 'threads'
set sort_aux = 'reverse-last-date-received'
set auto_tag = yes
set pager_index_lines = 10
ignore "Authentication-Results:"
ignore "DomainKey-Signature:"
ignore "DKIM-Signature:"
hdr_order Date From To Cc
alternative_order text/plain text/html *
auto_view text/html
bind editor <Tab> complete-query
bind editor ^T complete
bind editor <space> noop
# # Gmail-style keyboard shortcuts
macro index,pager am "<enter-command>unset trash\n <delete-message>" "Gmail archive message" # different from Gmail, but wanted to keep "y" to show folders.
macro index,pager d "<enter-command>set trash=\"imaps://[GMail]/Bin\"\n <delete-message>" "Gmail delete message"
macro index,pager gi "<change-folder>=INBOX<enter>" "Go to inbox"
macro index,pager ga "<change-folder>=[Gmail]/All Mail<enter>" "Go to all mail"
macro index,pager gs "<change-folder>=[Gmail]/Starred<enter>" "Go to starred messages"
macro index,pager gd "<change-folder>=[Gmail]/Drafts<enter>" "Go to drafts"
macro index,pager gl "<change-folder>?" "Go to 'Label'" # will take you to a list of all your Labels (similar to viewing folders).

Save and exit

Create script:

cd /home/pi/
sudo nano mailIP

Paste the following (repalce YOURMAIL with full email address of where you want the email sent i.e.

 #my_ip=`ifconfig | grep 'inet addr:'| grep -v '' | cut -d: -f2 | awk '{print $1}'`
 my_ip=`wget -q -O -|sed -e 's/.*Current IP Address: //' -e 's/<.*$//'`
 my_pi="Domoticz RaspberryPi has rebooted! "
 message="This is a mail from my Pi at $today. Current IP address = $my_ip"
 echo $message > message.txt
 mutt -s "${my_pi}" ${mailreciever} < message.txt

Save and exit

Make executable:

sudo chmod +x mailIP

Test it